The present invention relates to a robot traveling duct for a clean room, particularly but not exclusively a clean room for semiconductors, using a vertical laminar flow of air.
FIG. 1 illustrates a typical example of the semiconductor clean room C, using the prior art robot traveling duct. In the ceiling room, a high performance ceiling filter 1, such as HEPA (High Efficiency Particulate Air) filter, ULPA (Ultra Low Penetration Air) filter or the like filter, is provided to the whole ceiling for producing a vertical laminar flow of filtered air from the ceiling towards the floor of the clean room. In the robot traveling duct, the guide rail 3 of the robot 2 is supported on poles on the floor or suspended from the ceiling and is surrounded with a guide rail duct 5 along the overall length thereof. Semiconductor production units are located below the traveling path of the robot 2. The guide rail duct has a plurality of slits 6 for passing a connecting portion 2A of the robot, the connecting portion 2A slidably engaging with the guide rail 3. The inside of the guide rail duct 5 is evacuated by a conventional evacuating unit, not shown, so that cleaned air from the ceiling filter 1 is drawn through the slits 6 into the guide rail duct 5, from which it is sent to the evacuating unit, whereby dust which is produced due to the slidable contact between the robot connection portion 2A and the guide rail 3 is entrained in the air stream from the guide rail duct to the evacuating unit for preventing the dust from scattering in the clean room C.
In the prior art robot traveling duct, the vertical laminar flow of the filtered air from the ceiling filter 1 is disturbed blow it as shown by arrows in FIG. 1. When the disturbance of the laminar flow is large, dust in the filtered air is scattered in a wide area. This is not preferable for maintaining a superclean room.
Accordingly, it is an object of the present invention to provide a robot traveling duct which is capable of effectively preventing the vertical laminar flow of air from being disturbed below it.